This cold, fruity, quick-dissolve powder from Starbucks is appropriately named: Refreshers are intensely flavored, a breeze to make, and serve up 50 milligrams of performance-enhancing caffeine (extracted from unroasted coffee beans so there’s no bitterness or aftertaste).
“The boost provides enough lift to combat after-lunch laziness,” says one tester. Tip: Add a snowball, and enjoy a slushy treat. $6 (5 servings); 4.1 oz. starbucks.com